Energy storage device and method based on carbon dioxide gas-liquid phase change

An energy storage device based on carbon dioxide gas-liquid phase change, comprising:

• a gas storage reservoir, configured to store carbon dioxide in a gas state, wherein a volume of the gas storage reservoir is changeable;
• a liquid storage tank, configured to store carbon dioxide in a liquid state;
• an energy storage assembly, configured to store energy and arranged between the gas storage reservoir and the liquid storage tank, wherein the energy storage assembly comprising a condenser and at least one compressed energy storage part each of the at least one compressed energy storage part comprises a compressor and an energy storage heat exchanger, the carbon dioxide is changed from the gas state to the liquid state through the condenser;
• an energy release assembly, configured to release energy and arranged between the gas storage reservoir and the liquid storage tank, wherein the energy release assembly comprises an evaporator at least one expansion energy release part and an energy release cooler, each of the at least one expansion erergy release part comprises an expander and an energy release heat exchanger, the carbon dioxide is changed from the liquid state to the gas state through the evaporator, and the energy release cooler is configured to cool the carbon dioxide entering the gas storage reservoir;
• and
• a heat exchange assembly, wherein the heat exchange assembly comprises a cold storage tank, a heat storage tank, and a heat exchange medium cooler, the cold storage tank and the heat storage tank are provided with a heat exchange medium, the cold storage tank and the heat storage tank form a heat exchange circuit between the energy storage assembly and the energy release assembly, the heat exchange medium is capable of flowing in the heat exchange circuit, so as to transfer part of energy generated in the energy storage assembly to the energy release assembly, and the heat exchange medium cooler is configured to cool the heat exchange medium entering the cold storage tank;
• and
• a heat recovery assembly, wherein the heat recovery assembly is connected to the evaporator, and at least one of the condenser, the energy release cooler, or the heat exchange medium cooler is connected to the heat recovery assembly, such that at least one of energy released when the carbon dioxide is changed from the gas state to the liquid state, energy released when the carbon dioxide is cooled before entering the gas storage reservoir, or the energy released when the heat exchange medium is cooled, is capable of being recovered by the heat recovery assembly and transferred to the evaporator to be used in evaporation of the carbon dioxide in the evaporator.